Marches were today planned for 50 cities and towns around the country and thousands have gathered with placards calling on the government to #FundOurFutureNotGas.
The protesters want the Federal Government to withdraw support and subsidies for gas projects and instead fund renewable energy initiatives and First Nations-backed solutions for protecting the environment.
High school and university students are on strike from classes in a bid to get their message across, but there are many others at the rallies too.
Aerial photos from Sydney show thousands of people lining the streets around Town Hall.
The bleak weather meant many were sheltered under umbrellas.
In Brisbane, students gathered in King George Square and further south on the Gold Coast, a group protested on Surfers Paradise beach.
Union members joined students in Melbourne and in Adelaide, thousands blocked traffic on King William Street.
On the same day, the International Energy Agency called for an end to new coal mines, oil and gas wells.